Preventing diabetes - applying pathophysiological and epidemiological evidence

This is a review of research carried out in Japanese Americans that points towards possible approaches to prevention of type 2 diabetes mellitus. The natural history of type 2 diabetes usually includes both insulin resistance and beta -cell dysfunction. Insulin secretion may compensate for insulin r esistance. Alternatively, enhanced insulin sensitivity may mask an insulin secretory defect. Epidemiological data support the view that in the vast ma jority of cases of type 2 diabetes, insulin resistance is essential to the pathogenesis of hyperglycemia. Increased diabetes prevalence as ethnic grou ps migrate to more urban or westernized regions has been attributed to incr eased occurrence of insulin resistance. Research among Japanese Americans i n Seattle, Washington, showed a higher prevalence of type 2 diabetes than i n Japan, which suggested that factors associated with 'westernization' migh t be playing a role in bringing out underlying susceptibility to diabetes. Our research has shown that these impressions were correct and that the abn ormalities that characterize the metabolic syndrome play a significant role . Due to increased intra-abdominal fat deposition, Japanese Americans were likely to be 'metabolically obese' despite relatively normal BMI. A diet hi gher in animal fat and lower levels of physical activity were risk factors leading to increased intra-abdominal fat deposition, insulin resistance, an d diabetes. information from epidemiological studies such as these may be u sed to determine whether diabetes may be prevented through changes in lifes tyle or application of specific therapies targeted towards identified metab olic abnormalities.